carbon cycle


Definition of carbon cycle

1 : the cycle of carbon in the earth's ecosystems in which carbon dioxide is fixed by photosynthetic organisms to form organic nutrients and is ultimately restored to the inorganic state (as by respiration, protoplasmic decay, or combustion)
2 : a cycle of thermonuclear reactions in which four hydrogen atoms synthesize into a helium atom by the catalytic action of carbon with the release of nuclear energy and which is held to be the source of most of the energy radiated by the sun and stars

Examples of carbon cycle in a Sentence

Recent Examples on the Web

The carbon cycle is the process in which carbon circulates in various forms through Nature. Martin Finucane,, "MIT professor renews warning about the possibility of mass extinction event in ocean," 11 July 2019 According to Curtis Suttle, a microbial ecologist at the University of British Columbia, viruses play a major role in global biogeochemical cycles, including the carbon cycle, whereby carbon moves between Earth’s biosphere and atmosphere. Quanta Magazine, "Scientists Discover Nearly 200,000 Kinds of Ocean Viruses," 25 Apr. 2019 Clearing land for ranching or agriculture and fossil fuel emissions are the biggest influences on the carbon cycle. Sarah Gibbens, National Geographic, "Plants help absorb our carbon, but for how much longer?," 16 May 2019 Balancing act For comparison, the researchers also used the positive feedback response of the Earth’s carbon cycle from climate models. Scott K. Johnson, Ars Technica, "The economic impacts of climate change could limit climate change," 19 Dec. 2018 Scientists are still trying figure out how much carbon dioxide is soaked up by the land and the ocean in the planet’s natural carbon cycle. Chelsea Harvey, Scientific American, "CO2 Can Directly Impact Extreme Weather, Research Suggests," 21 June 2018 This circular voyage is the short-term carbon cycle. Moises Velasquez-manoff, New York Times, "Can Dirt Save the Earth?," 18 Apr. 2018 Shrinking ice sheets shifted the carbon cycle in a way that raised atmospheric CO2, further warming the planet. Scott K. Johnson, Ars Technica, "Ars answers a federal judge’s questions about climate change," 19 Mar. 2018 These are questions about the carbon cycle—the many interconnected processes by which carbon changes forms and moves throughout the Earth’s atmosphere, oceans, land ecosystems, and even rocks. Scott K. Johnson, Ars Technica, "Ars answers a federal judge’s questions about climate change," 19 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'carbon cycle.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of carbon cycle

1901, in the meaning defined at sense 1

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26 Jul 2019

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The first known use of carbon cycle was in 1901

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carbon cycle


Medical Definition of carbon cycle

: the cycle of carbon in living beings in which carbon dioxide is fixed by photosynthesis to form organic nutrients and is ultimately restored to the inorganic state by respiration and protoplasmic decay

More from Merriam-Webster on carbon cycle

Rhyming Dictionary: Words that rhyme with carbon cycle Encyclopedia article about carbon cycle

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